Lifepo4 cold temp cut off 23F or 32F?
Reading on LFP cold cut off I see Expert Power has 23F as there cut off on there batteries and I thought it was 32F? Expert Power wrote: Question: Do these have low temperature protection. Will t...
Forum Discussion
I believe there's general agreement the majority of lifepo4 manufacturers specify >32f as the minimum temperature you can "safely charge" a lifepo4 at it's maximum rated charge current. Safely charge defined as charging that results in no reduction in a lifepo4's long-term performance---the ability to deliver 3000-4000 charge cycles while maintaining at least 80% of the original ah rating of the battery.
As StirCrazy alluded to earlier, if a particular manufacturer specs their lifepo4 as capable of maximum charge current at <32f, my guess, it's just a marketing strategy. Their bean-counters have probably determined any increased costs for warranty claims (to support the lower charge cut-off temp) is more than offset by the increased sales to folks who actually believe they have a better lifepo4. Again, more than likely marketing strategy vs. a battery/cell with any real added capability.
Lastly, some see the lifepo4 32f low-temp charge cut-off as all or nothing in terms of charging--ok to charge at 33f---not ok to charge at 32f. That's not necessarily the case. It is possible to safely charge at <=32f . . . if you're willing/able to reduce the charge current (and have a BMS which permits charging at <=32f). I find it very interesting that Trojan actually specs the maximum allowable charge current for their 110a Trillium lifepo4 down to -4f (-20c).
As StirCrazy alluded to earlier, if a particular manufacturer specs their lifepo4 as capable of maximum charge current at <32f, my guess, it's just a marketing strategy. Their bean-counters have probably determined any increased costs for warranty claims (to support the lower charge cut-off temp) is more than offset by the increased sales to folks who actually believe they have a better lifepo4. Again, more than likely marketing strategy vs. a battery/cell with any real added capability.
Lastly, some see the lifepo4 32f low-temp charge cut-off as all or nothing in terms of charging--ok to charge at 33f---not ok to charge at 32f. That's not necessarily the case. It is possible to safely charge at <=32f . . . if you're willing/able to reduce the charge current (and have a BMS which permits charging at <=32f). I find it very interesting that Trojan actually specs the maximum allowable charge current for their 110a Trillium lifepo4 down to -4f (-20c).
